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Energy shock: when your bill is a nasty surprise and may be months or years old!


An unexpectedly high bill can be a big energy shock. But what if it’s months or years out of date and might even be someone else’s responsibility?   

Post #3 in our Navigating Energy Challenges series

By Victoria Wan

According to National Citizens Advice data for 2024, energy billing problems are our clients’ most common concern; and nearly a quarter involve unexpected catch-up bills [1].

At Citizens Advice Epsom & Ewell we often see clients struggling with back billing of this kind. With the cost of living already straining many households, these retroactive charges can add significant financial pressure.

What is back billing?

Energy suppliers can typically only back-bill you for up to 12 months. They have longer if they have made a reasonable and verifiable attempt to read your meter or contact you. Other exceptions include where the supplier sent a bill before the year passed and the customer did not pay.

Smart meters and back billing: a client’s experience

Smart meters should make back billing unnecessary by providing regular and accurate readings. But problems can still arise:

  • Switching suppliers: meter-reading errors during the switch can lead to catch-up charges
  • Faulty meters: inaccurate readings may cause underestimated usage to build up over time.

Our client faced a large back bill after switching from an old to a new smart meter; their supplier was blaming a fault in the old meter. Under back-billing rules the supplier had applied a substantial credit but there were still outstanding costs. The client sought a free meter test, tariff confirmation, and a supplier switch. We contacted the supplier on client’s behalf, disputed the back-bill amount and worked to resolve the issue. 

Tips to avoid back billing

Regular meter readings: even with smart meters, confirm it is sending accurate data. 

How Citizens Advice helps

If you are facing a back bill or having issues with your meter, we can:

  • Help you understand your rights.
  • Negotiate with your supplier.
  • Explore payment options.
  • Advise on switching suppliers or tariffs.

Don’t let back billing catch you off guard. If you’re having energy problems of any kind our Energy Advice Service can help. Contact us for free help and how to avoid an energy shock and stay confident about your energy bills.

Victoria Wan is a Research & Campaigns Volunteer at Citizens Advice Epsom & Ewell.



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